xAI Launches Grok Voice Think Fast 1.0 — Tops Tau Voice Benchmark at 67.3%

xAI·medium signal

xAI released grok-voice-think-fast-1.0 on April 25, an in-house voice agent model that outperforms Gemini, GPT Realtime, and xAI's own predecessor on the Tau Voice Benchmarks. The entire voice stack — VAD, tokenizer, audio models — was built from scratch. Already deployed at scale powering Starlink's live phone operations, targeting high-stakes multi-step workflows in retail, airline, and telecom.